The invention relates to a metal laminate gasket with mutual laminating portions around a hole to be sealed.
An internal combustion engine has been developed to provide high power and light weight. A cylinder head gasket installed between a cylinder head and a cylinder block has been developed to satisfy the requirement of the engine. Since a metal laminate gasket is strong against high temperature, the metal laminate gasket has been used widely.
In order to form a light weight gasket, it is preferable to reduce a number of metal plates laminated together. Therefore, a metal gasket formed of two metal plates has been used.
When a metal laminate gasket is formed of two metal plates, one metal plate may be turned around a hole to be sealed to provide a flange around the hole. In this case, the flange is generally laminated directly over a base portion of the one metal plate without laminating over the other metal plate, because the thickness of the gasket at the flange is not increased, or the other plate is used as a surface pressure regulating plate for a curved portion between the flange and the base portion. In the later case, the other plate must have a thickness equal to or greater than that of the flange, and the flange and the other plate can not be laminated together. This kind of gasket is shown in U.S. Pat. No. 4,938,488.
When the two plates are simply laminated, the two plates are easily disassembled, so that the two plates must be connected together by other means, such as spot welding.
On the other hand, when a metal gasket requires a high surface pressure around a hole to be sealed, a surface pressure regulation plate or shim may be fixed around the hole (U.S. Pat. No. 4,776,073). A metal ring may be formed between a flange and a base portion of one metal plate to provide a certain thickness therebetween around a hole (U.S. Pat. No. 5,058,908).
The above patents operate as intended. However, in a thin metal laminate gasket, it is desirable to connect the metal plates easily without a spot welding or other special means.
Accordingly, one object of the invention is to provide a metal laminate gasket, wherein two metal plates can be easily connected together.
Another object of the invention is to provide a metal laminate gasket as stated above, wherein a surface pressure around a hole to be sealed can be regulated easily.
A further object of the invention is to provide a metal laminate gasket as stated above, wherein the appearance of the gasket is improved.
Further objects and advantages of the invention will be apparent from the following description of the invention.